Radio frequency integrated circuit having a physical layer portion integrated therein

Abstract

A ZigBee-compliant radio frequency LSI includes a physical layer portion and a modulator. The physical layer portion has an RF portion, a demodulator, a data transmission and reception control, and a transfer mode determination portion. The transmission and reception control converts, during reception, symbol data received by the demodulator into the byte data received, and outputs, during transmission, the symbol data to be transmitted to the modulator. The determination portion determines, when the first identification data in the received data from the RF portion necessary for determining the received data transfer mode are fixed, the data length of the subsequent second identification data. The determination portion latches, when data corresponding to the determined length of the second identification data are fixed, the data necessary for determining the received data transfer mode to transfer the data to the MAC layer.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a radio frequency integrated circuit, and more specifically to a radio frequency large-scale integrated circuit (LSI) which has its physical-layer interface compliant with IEEE (Institute of Electrical and Electronics Engineers) 802.15.4 and which is based upon ZigBee (trademark of ZigBee Alliance) technology. The invention more particularly relates to the control of receiving data in the radio frequency integrated circuit. [0003] 2. Description of the Background Art [0004] ZigBee is one of the short-range radio frequency communication standards and classified into the radio frequency communication standard which uses sixteen channels into which divided is the same frequency bandwidth of 24 GHz as the wireless local area network (LAN) standard, IEEE 802.11b. [0005] Conventional radio frequency integrated circuits, sometimes simply referred to as “radio frequency LSIs”, using ZigBee t...

AI Technical Summary

Benefits of technology

[0021] It is an object of the present invention to provide a radio frequency integrated circuit capable of allotting more time to providing the MAC layer of ZigBee with information data for determining a transfer mode and to determining the transfer mode by the MAC layer, thereby satisfying much more requests from users.

[0025] According to an aspect of the present invention, at the time point at which the data necessary for determining the received data transfer mode are fixed in the physical layer portion, the physical layer portion latches the data and notifies the MAC layer, so that, during receiving subsequent data, the network layer can transfer the data and the MAC layer can determine the transfer mode. This can provide more time for the transmission of information for the transfer mode determination to the MAC layer and for the transfer mode determination by the MAC layer, thereby allowing more requirements from users to be satisfied.

[0026] According to another aspect of the invention, the radio frequency LSI comprises the MAC layer, so that the radio frequency LSI can perform the complicated MAC process thereinside, thereby making it possible to implement and control the ZigBee network with a host processor with lower performance, such as an 8-bit processor. Furthermore, the radio frequency LSI with the built-in MAC layer comprises the physical layer portion, and, at the second time point at which data necessary for determining the received data transfer mode are fixed in the physical layer portion, the physical layer portion latches the data and notifies the MAC layer, so that the MAC layer burden can be decreased and the MAC layer can be notified more rapidly of information on the field, Addressing Field, for example, thereby improving the performance of the series of data transfer process.

Problems solved by technology

The non-beacon mode thus cannot save power with the intermittent operation unlike the beacon mode.

In this method, the end devices periodically send out requests to the base station before receiving the downstream data, thereby causing a transmission delay in the downstream communication.

The above-described conventional radio frequency LSI, however, suffers from the following problems.

Furthermore, since the system is structured such that entire data of up to 133 bytes are received by a physical layer and thereafter data necessary for transfer retransmitted to the outside MAC layer, it may be belated that the MAC layer determines the transfer, thereby causing the radio frequency communication system to be deteriorated in specifications, or performance.

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